The HT813 is an analog telephone adapter with one FXS analog telephone port and one FXO PSTN line port to provide emergency line support over PSTN lines. Integrating the FXO and FXS ports enables this hybrid ATA to support remote calling to and from PSTN lines. For added flexibility, the FXS port extends VoIP service to a single analog device. Users can convert their analog technology to VoIP thanks to the HT813's ultra-compact size, HD voice quality, advanced VoIP functionality, advanced security protection, and multiple auto-provisioning options. These advanced features allow service providers to offer their customers high-quality IP services, including the ability to upgrade to VoIP.